i have a 87 5.0 roller in my 66 mustang. i had 289 hipo heads on it with adjustable rocker and 550 springs. it was bending pushrod and beat the top of the valve stems like a mushroom. so i went to ebay and bought a set of procomp aluminum heads 202 160s 190cc and 600 lift single springs. for everyone that said these heads are junk at about 4000 rpm with the f cam this car pulls like a freight train. but when i got the heads it said to use .100 longer push rods. the car was doing good then it bent another pushrod. does anybody have a set of pro comps on a 5.0 and can tell me what lenght pushrod to run. i know that i should check push rod lenght but just tryin to get close. any help would be great. i do run this car about 6-7000 rpm thank u. i also posted this in 5.0 forum

 

Sounds like it's NOT the heads but either 1 Your valves are floating 2 Need to get different Piston heads with the valve groves in them 3 different ratio rockers and stiffer springs

 

Which pushrods are you using? Hardened I hope. What length and for what engine?